1. Field of the Invention
The present invention relates to a plug for use in a beverage container such as a thermos bottle. Particularly, the present invention relates to a plug having a valve structure, and allowing a content fluid to be poured out when attached to a beverage container.
2. Description of Related Art
Conventionally, as a plug of such kind, there has been disclosed an inner plug structure (e.g., Japanese Patent No. 4514692) for use in a fluid container. This inner plug structure includes: an inner plug main body detachably attached to an opening section of a container main body; a fluid passage that is formed inside the inner plug main body, and connects an inlet and an outlet that are respectively opened toward an inner side and an outer side of the container main body; a valve body biased in a direction allowing the inlet of the fluid passage to be closed; a cover that is disposed on an upper end of the inner plug main body and serves to close an upper opening section thereof; and a control switch that is provided on the cover and is capable of being slid back and forth such that the valve body can be opened and closed. Further, while a first engagement portion is provided on either one of the inner plug main body and the cover, a first engageable portion engageable with the first engagement portion is provided on the other. Here, an elastic section is provided on the upper end of the inner plug main body. Particularly, while a second engagement portion is provided on either one of the elastic section of the inner plug main body and the cover, a second engageable portion engageable with, the second engagement portion is provided, on the other. This inner plug structure is simpler than a conventional structure where coupling portions are provided on whole circumferences of the inner plug main body and the cover. Moreover, since a force used to slide the control switch is applied in a horizontal direction, i.e., a direction other than a disengagement direction, the inner plug structure shall not be disassembled involuntarily.